Union team manager Peter Nowak is still sifting through his lineup, attempting to fill half his starting back line for Saturday's 6 p.m. home opener at Lincoln Financial Field against D.C. United.

"It's still early in the week," Nowak said after Monday's practice. He must replace two defenders - Toni Stahl, who will miss the game after receiving a red card in the opening 2-0 loss at Seattle, and David Myrie, who was released last week.

Nowak said his team is close to coming to terms with 30-year-old defender Cristian Arrieta, who has been working out with the team. Arrieta could start if he is signed, Nowak said.

Another possible starter in the back line could be veteran Shavar Thomas, the 29-year-old Jamaican National Team veteran, Nowak said.

And another possibility is using Michael Orozco, a skilled defender, who started as a defensive midfielder against Seattle, Nowak said. Then again, Orozco impressed Nowak in the midfield and could very well remain there.

"Michael is very smooth on the ball and can see things developing in front of him," Nowak said.

The Union is also considering signing 24-year-old former D.C. United midfielder Danny Szetela.

"He's coming off surgery and we have to make sure he's healthy," Nowak said of Szetela.

The Union will be aided by the return of midfielder Fred, who sat out the opener after receiving a red card in last year's regular season finale while playing with D.C. United.

"I'll do whatever the team needs," said Fred, a Brazilian who like many players from his country only uses one name. "I'm looking forward to getting back on the field."

Notes: Television station 6ABC or its sister station, Live Well HD Network, will broadcast live the Union's games that aren't on national TV. . . . J.P. Dellacamera will call the games, and former MLS player Kyle Martino will serve as analyst. . . . Saturday's game will air on the Fox Soccer Channel.